P2A00 after changing upstream A/F sensor
 

Changed out the front A/F sensor on my 2008 GD3 yesterday with a Denso 234-9060 (which Denso lists as the replacement part) , but it threw a P2A00 after a couple of drives. Put the old original sensor back (Denso 211200-2380), and it's back to normal. Any other conclusion other than a duff sensor out of the box?

Where you got your sensor from and how much was it?
Same part number is sold at Autozone and is considered OEM part (although wire crimp looks different).
Assuming that new sensor looks like on the picture from Autozone website, it is a) defective out of the box; b) OEM-retail part (which is "slightly" inferior to one specifically made for Honda, c) counterfeit or copy made in China sold in the US.
PS IMHO, I'll prefer lightly used genuine part to new aftermarket in most cases to achive expected fit, performance and longevity.

I like to be proactive most of the time, but with the price of the OEM sensor ($250+), I'd probably return the one you bought and just keep running the original. If it's not throwing a code, I'd just not replace it.

Picked it up from Amazon for $100 (Autozone is super-proud of that sensor). A bit less than what Rockauto would charge for the same part, but since I get free shipping through Amazon, seemed like a reasonable thing to do. If it's a counterfeit, it's one hell of a good job.

I've got a replacement on order. If that one also fails, guess I'll run the original until it craps out. Seems like the likelihood of finding a low-mileage junkyard pull from a 2007 / 2008 is pretty low.

I suppose, but 125K miles on the original sensor seems to be living on borrowed time, especially since the engine was running rough as a cob when I bought it (since fixed with new plugs & coils), so that sensor's had to put up with a lot of crap. $100 bucks and 30 minutes of my time seemed to be worth it. If the option is $250+, yeah, she's gonna run the original until it craps out.

I like the way you think. Definitely appreciate someone that wants to take care of their car.

FWIW, ours is still OK with the original at 190k miles, but ours has never had to put up with too much. Have had a plug back out twice which led to one coil going bad, but it was not driven many miles while running poorly and never threw a code.

Denso is good stuff. I'm surprised it's giving you trouble.

According to the TSB some A/F sensors were failing due to corrosion of the heater. Other thing that is killing many sensors is the chemical contamination (if engine uses oil). Raw fuel in the exhaust is more dangerous to the catalyst than to a/f sensor.

Yeah, I'm really not that big on car mods (other than upgrading the tunes section), but I really, really dislike badly-maintained machinery.

The Fit is one of my "newer" rigs. I've got a 95 Camry that I've had since it was new, an 2002 Sequoia, and a 2014 Prius. Haven't had to do much to the Prius except oil and filter changes, but the other two are chock full of Denso, Mitsuboshi, Koyo, NGK, and Aisin parts (all Toyota OEM suppliers, and all excellent quality). Never had trouble before that wasn't my fault in the end.

Yeah, saw that TSB. Thing is, my original F/A sensor still works, I was just changing it out on general principles. Near as I can tell, this new part number (234-9060) is the redesigned one that is more resistant to moisture damage.

Update: got the new A/F sensor in, and it throws both a P2A00 and a P1172, so it's even worse that the last one.

Took a closer look at the supplier, and those jokers (AD Auto Parts), even though they're selling through Amazon, seem to have a rep for selling dicey parts.

This new one's going back, and I'm going to bitch like hell to Amazon about these guys.

Guess I'll do what I should have done in the beginning -- order from Rockauto. Never had a problem with parts from those guys.

Sheesh.

My co-worker bought replacement window motor off e-ba new seller ; the motor was a mummy that worked only without load (3 pole commutator with lousy spring type brushes (not carbon brushes)

Third update: got my Denso A/F sensor in from Rockauto yesterday (same part number), and it's working like a champ. Amazon gave me full credit for both the duff sensors from AD Auto Parts (plus free shipping back to them), so I'm only out for my time. And, hey, I've gotten really good at replacing the upstream A/F sensor :wiggle:

Lesson learned: ordering parts from third-party sellers on Amazon is almost a big of crapshoot as ordering parts from fleabay. When I get around to replacing my starter (which is starting to do that cold-weather grind that Denso starters like to do), it'll be Rockauto again :)

This is I typically use only 2 places to get my parts: DEALER OR JUNK YARD:)
NAPA can get you OEM part trough Altrom distributor

Because I don't have many junk yards near where I live, I use two places...dealer and Rock Auto.